The diamond cut is the most important element to consider when buying a diamond. The cut is the biggest factor in creating sparkle and fire, and without a high cut grade even a diamond of high quality can appear dull and lifeless. A diamond cut poorly and too deep can face-up smaller than it actually is.
The cut of a diamond not only refers to the diamond’s shape, it also refers to how effectively the diamond returns light back to the viewer’s eye. A well-cut diamond will appear very brilliant and fiery, while a poorly cut diamond can appear dark and lifeless, regardless of its color or clarity. Not only do well-cut diamonds appear more brilliant, they also tend to appear larger than other diamonds of the same carat weight. An ideal diamond has both increased brilliance and diameter relative to more deeply-cut diamonds.
A well-cut diamonds exhibit three different properties: brilliance, dispersion and scintillation. As light strikes a diamond's surface, it will either reflect off the table of a polished stone or enter the diamond. The light that is reflected off the diamond is known as the diamond's brilliance. As light travels through a stone, some of the light rays are separated into flashes of color. This is known as dispersion. The result of dispersion—the separation of white light into its spectral colors— is known as fire. Scintillation is flashes of color that are viewable as an observer moves a diamond back and forth.
Excellent Cut Diamonds provide the highest level of fire and brilliance. Because almost all of the incoming light is reflected through the table, the diamond radiates with magnificent sparkle.
Very Good Cut Diamonds offer exceptional brilliance and fire. A large majority of the entering light reflects through the diamond’s table. To the naked eye, Very Good diamonds provide similar sparkle to those of Excellent grade
Good Cut Diamonds showcase brilliance and sparkle, with much of the light reflecting through the table to the viewer’s eye. These diamonds provide beauty at a lower price point.
Fair Cut Diamonds offer little brilliance, as light easily exits through the bottom and sides of the diamond. Diamonds of a Fair Cut may be a satisfactory choice for smaller carats and those acting as side stones.
The GIA diamond colour scale is the leading industry standard of diamond colour grading. Before this was the standard, other colour grading scales used A, B and C, so GIA started their scale at D to avoid confusion.
There are six categories on the GIA diamond chart, with colour grades that range from absolutely colourless to light in colour. Diamonds rated D are the most devoid of colour and very rare, whereas G colour diamonds and H colour diamonds are near colourless, and since they’re priced lower they are excellent value diamonds. The more you move down the colour chart, the lower the colour grade is, and the more noticeable the light yellow hue becomes.
D: Absolutely colourless. The most rare and valuable. Less than 1% of diamonds mined worldwide are graded as colour D.
E - F: Also considered colourless, even though it is a minimal trace of colour that can only be detected by an expert gemmologist. Less rare than D, and more valuable than G – H.
G - H: Near colourless. To the naked eye these diamonds appear clear and colourless, although they also contain minute traces of colour. Less rare than E –F, but more valuable than I – J.
I - J: Near colourless with a faint tint of yellow. Less rare than G – H, but more valuable than K – L.
K - L: A faint yellow tint that is visible to the eye. Less rare than I – J, but slightly more valuable than M – N.
M - Z: A very light yellow tint, easily identified by the eye. Least valuable of the diamond colour grade.
If you're looking to buy fine diamond jewellery such as an engagement ring, it's important to understand how diamond colour affects price. Here are a few buying tips and things to know about diamond colour.
When it comes to diamonds, less colour means higher quality. While brilliance is the first thing you notice about a diamond, colour is the second. The higher the colour grade, the less colour there is, and the more expensive it will be.
For the best value, choose G-J diamond colour grades in the Near Colourless category. With these diamonds, the naked eye can’t discern any colour. The visible difference between diamonds of one colour grade (G-H or I-J) is so minor it's difficult to detect with the unaided eye, but the cost savings can be significant. Keep this in mind when choosing your diamond colour grade.
In general, to avoid a pale yellow colour, choose a diamond grade H or higher. For the purist, look for a D to F grade colourless diamond, which will have no discernible colour under magnification.
Diamond shape, size and your ring’s metal setting can visually impact diamond colour.
Setting — Pairing diamonds with similar toned metals can neutralize colour in the diamond. Consider setting higher colour grade diamonds like Near Colourless diamonds (G-J) in yellow gold and Colourless diamonds (D-F) in white gold or platinum. A gold setting may show through a colourless diamond
Diamond Shape — Some diamond shapes may show or mask colour to varying degrees. For example, brilliant-cut shapes such as round and princess reflect more light, which means more colour is masked. Step-cut diamonds (emerald and Asscher cuts) may show more colour because they are cut with fewer facets, resulting in bigger "windows" through which to see the colour.
Fancy shaped diamonds, like pear and marquise may also show slightly more concentrated colour at their points.
Diamond Size — Colour is easier to see in larger diamonds. If you want a diamond above 1 carat, choose a G or H coloured diamond. I-J colour diamonds are best when just under a carat.
Clarity refers to how clean or clear the diamond is with respect to natural microscopic characteristics that were trapped within or on the diamond while it was forming. Internal characteristics are known as inclusions, and characteristics on the surface of the gem are known as blemishes. Inclusions may be crystals of a foreign material or structural imperfections such as tiny cracks, known as feathers, which can appear whitish or cloudy
Often times the inclusions are microscopic diamonds that were absorbed by the larger crystal before the diamond was carried to the surface of the Earth. The quantity, size, color, location, orientation, and visibility of inclusions all affect the final clarity grade of a diamond. Diamonds with no or few inclusions are considered particularly rare and highly valued
Because diamonds formed deep within the earth, under extreme heat and pressure, they often contain unique birthmarks, either internal (inclusions) or external (blemishes).
Diamond clarity refers to the absence of these inclusions and blemishes. Diamonds without these birthmarks are rare, and rarity affects a diamond’s value. Using the GIA International Diamond Grading System™, diamonds are assigned a clarity grade that ranges from Divour diamonds to diamonds with obvious inclusions (I3).
Every diamond is unique. None is absolutely perfect under 10× magnification, though some come close. Known as Divour diamonds, these are exceptionally rare. Most jewelers have never even seen one.
The GIA Clarity Scale contains 11 grades, with most diamonds falling into the VS (very slightly included) or SI (slightly included) categories. In determining a clarity grade, the GIA system considers the size, nature, position, color or relief, and quantity of clarity characteristics visible under 10× magnification.
Carat (ct.) refers to the unique unit of weight measurement used exclusively to weigh gems and diamonds. Carat weight is often confused with visual size even though it is actually a measurement of weight. Depending on the shape and type of gemstone being weighed, the weight will visually show itself differently. For example, a 1.00 ct. round diamond will measure around 6.5mm, and a 1.00 ct. round sapphire will measure around 6.0mm. This is due to the varying density of different gemstones. Total carat weight (t.c.w.) is a phrase that represents the total weight of all diamonds or other gemstones in a piece of jewelry, when more than one gemstone is used. Diamond solitaire earrings, for example, are usually quoted in t.c.w., indicating the combined weight of the diamonds in both earrings.
Once cut, color, and clarity grade have been determined, the carat weight of a diamond can be easily established to fit within a budget. Larger diamonds are much more valuable because they are discovered in nature much less frequently than small ones. Diamond prices actually rise exponentially with carat weight rather than linearly. For example, a 1.00 ct. diamond of a given quality is always valued higher than two 0.50 ct. diamonds of the same quality. In fact, a general rule of thumb is that a diamond of double the weight costs around four times more. “Under-sizes” are diamonds that weigh just below a cutoff weight. While fewer exist, they may represent an enhanced value. They are more difficult to find as a diamond cutter will choose to sacrifice beauty in order to cut a diamond with a weight that reaches one of the cutoff weights, or “magic numbers” as they are known in the industry. The cutoff weights are 0.50 ct., 0.75 ct., 0.90 ct., 1.00 ct., 1.50 ct., and 2.00 ct.
Carat is a term that refers to the weight of a diamond. Prior to the twentieth century, diamonds were measured using carob seeds, which were small and uniform and served as a perfect counter weight to the diamond. The word "carob” is the origin of the word "carat" that we use today.
Diamond Size and Diamond Carat Weight
The size of a diamond is proportional to its carat weight. When rough diamonds are cut and polished into finished diamonds, up to 2/3 of the total carat weight may be lost. Since larger rough gems of high quality are found less frequently than smaller rough gems of high quality, a single two carat diamond will be more expensive than two one-carat diamonds of the same quality.
In the United States, the majority of diamonds used in jewelry and sold as loose diamonds are one carat or less in weight. The average engagement ring diamond sold in the U.S. is less than 1/2 carat in weight.
A diamond will increase in weight much faster than it increases in actual "face-up" diameter. For example, while an ideal cut one-carat diamond measures approximately 6.5mm in width, a diamond of twice its weight measures only 8.2mm wide—less than a 30% increase. The graphic to the left helps illustrate this point.
Which Carat Weight Is Right For You?
This question has no direct answer. It is a choice that depends on personal preference and budget. When looking at a diamond engagement ring, what is most visible is the size of the surface area on the top of the diamond. It is difficult to measure a diamond’s carat weight simply by looking at it. Although carat weight influences cost quite a bit, it is advisable to focus on diamond cut and diameter.
When starting your search for an engagement ring, choosing the shape of the central diamond is a great place to start. The most popular of diamonds for engagement rings are the Round brilliant diamonds, this is down to the abundance of fire, life and brilliance, they simply are the most sparkly.
Diamonds fall into two categories, brilliant cuts which are those cut to optimise light return throughout the stone, and Step cuts which are designed to showcase the clarity of the diamond. Examples of brilliant cut diamond shapes are: round, cushion, princess & pear, whilst emerald and asscher are examples of step cut diamonds. It is important to remember that diamond shape is not the same as diamond cut.
Brilliant cut diamonds showcase luminosity of the diamond. Step cuts, on the other hand, are designed to showcase the clarity of the stone. Here, elongated parallel facets make up the pavilion section. The diamond still sparkles beautifully, but there is an emphasis on the purity and elegance of the stone. Step cuts include emerald and asscher shapes.
Remember that shape is not the same as cut – the shape of a diamonds comes from cutting it but the shape is essentially the overall geometry or form of the diamond(emerald, round, square ect. The cut of a diamond is the facets and proportions- the thing that gives the diamond it brilliance and fire.
CUT is one of the Four Cs (also including COLOUR, CLARITY and CARAT), and is also a very important consideration when choosing a diamond.
While some shapes are more popular than others, and some provide better value for money, the most important thing is to choose a diamond that suits your bride-to-be. Think about her own personal style, and how that can be reflected in a precious gem. Gentle, fiery, quirky, bold or romantic – there is a diamond shape out there for everyone.
Perfect for classic looks, the round-cut diamonds are the most popular of all shapes. About 70 per cent of diamond engagement rings are set with round-cut diamonds. They have been carefully engineered to produce the most sparkle. With a well-cut round diamond, the brilliance and dispersion will impress in any engagement ring. Better yet, even though this diamond shape won’t have the largest face-up area, its intense sparkle will make it appear bigger!
The princess cut diamond is one of the most brilliant diamond shapes and, compared to a round, comes at a 25-35 per cent discount. Princess cut diamonds are brilliant cut like their round counterparts but are instead crafted into opulent square shape. Although princess cuts have a slightly smaller face-up size, their long diagonal measurement makes them seem larger. The most popular of the fancy shapes, princess cuts look great in any setting!
Cushion cut diamonds show excellent fire! The angles in this cut are made for those flashes of coloured light. The cushion cut features rounded edges that create a gentle pillow like shape. The cushion cut is one of the oldest diamond cuts and has been around for around one century longer than round cuts. Cushion cuts were the most popular for a long time and they are still quite popular.
This shape was originally developed for emeralds. Instead of the usual brilliance and fire, emerald cut is a step cut with a different kind of sparkle. These diamonds reflect light in a beautiful and subtle “hall of mirrors” effect.
Because of their elongated shape, emerald cut diamonds have tended to have a slimming effect on the finger. They can be set in an East-West setting for a more understated look.
The mesmerising windmill pattern of an asscher-cut diamond is both unique and eye catching. This shape complements both a contemporary solitaire and a vintage, Art Deco look. This cut was first developed in the 18th century by Joseph Asscher. With their octagonal outlines, they’re perfect for geometrical styles.
Radiant cuts are one of the most brilliant cuts a diamond can have. This cut provides tons of sparkle, and the truncated corners make it more durable than a princess cut. It is essentially a rectangular cut, which has been cut using the facet pattern applied to round brilliants and princess cuts. If you go with an elongated radiant cut, it may also appear larger than a round.
Very chic and feminine, oval cut diamonds still have most of the brilliance of rounds, but their elongated shape has a lengthening effect on the finger. Their symmetrical shape can make a relatively small diamond appear larger.
They are also a popular choice for East-West settings.
Not only do pear-shaped diamonds have a characteristic tear drop design. The pear shaped diamonds have a unique and beautiful shape, which are intensely radiant and flattering on the finger. Their elongated shape also makes them a great choice for trendy East-West engagement rings.
The elongated shape of a marquise cut makes the diamond look huge and your finger appear slimmer, too! Tapered to a point on either end, the marquise cut is fearless and bold. Marquises also have the largest face-up area of all diamond cuts around 15% larger than round cuts. They also look great set in East-West style engagement rings.
As its name suggests, this diamond is in the shape of a heart. Pretty and romantic it is the ultimate symbol of love and romance. Heart cut diamonds are a fancy cut and contains 56-58 facets that capture and reflect light, resulting in visible brilliance.
While every diamond is unique, all diamonds share certain structural features. A diamond’s anatomy, or its basic structure, determines its proportions, brilliance, dispersion and scintillation. Each part of the diamond has a specific name, and having a basic understanding of how each part contributes to the diamond as a whole will help you find your perfect diamond.
A diamond is comprised of the eight main components. They are Diameter, Table, Crown, Table Spread, Girdle, Pavilion, Depth, and Culet. Below is a brief description of each part of a diamond and its location.
Diameter: The width of a polished stone, measured from edge to edge.
Table: The largest polished facet located on the top of the diamond.
Crown: The top part of a diamond extending from the table to the girdle. The crown is made up of bezel facets (crown mains), star facets, upper girdle facets (upper halves), and a table facet.
Girdle: The very edge (widest edge) of the diamond where the crown and pavilion meet.
Pavilion: The bottom part of a diamond extending from the girdle down to the culet.
Depth: The total height of a diamond measured from the table to the culet.
Culet: The small or pointed facet at the very bottom of the diamond.
Before purchasing a diamond, make sure that you have a basic understanding of a diamond’s anatomy. This will allow you to truly appreciate diamonds and all their intricacies, communicate with experts about a particular diamond, and, most importantly, it will assist you in making a well-thought out decision about which diamond is best for you.
An ideal cut diamond is a round, brilliant, or princess cut diamond that is cut to ideal proportions and angles and has excellent polish and symmetry ratings. An ideal cut diamond reflects almost all the light that enters it, and is among the rarest cuts. The ideal cut diamond is used as benchmark for grading all other diamonds.
Ideal diamonds are perfectly proportioned to refract light, producing that fire and brilliance up through to the table and crown. There are at least six “ideal cuts” being used today but only three of them (including the one by Tolkowsky ) are the most common.
Exceptional diamond colour can be traced to the lattice of carbon atoms that form a diamond’s microscopic structure. Over billions of years, coloured diamonds were formed through exposure to heat, natural radiation or the saturation of natural elements. These incredibly rare processes result in beautiful tones and deep saturations of colour that evoke a deeply personal response in each of us.
Diamonds in the normal color range are colorless through light yellow and are described using the industry’s D-to-Z color-grading scale. Fancy color diamonds, on the other hand, are yellow and brown diamonds that exhibit color beyond the Z range, or diamonds that exhibit any other color face-up. These rare specimens come in every color of the spectrum, including, most importantly, blue, green, pink, and red.
Gem diamonds in the D-to-Z range usually decrease in value as the color becomes more obvious. Just the opposite happens with fancy color diamonds: Their value generally increases with the strength and purity of the color. Large, vivid fancy color diamonds are extremely rare and very valuable. However, many fancy diamond colors are muted rather than pure and strong.
The remarkable hue of yellow and orange diamonds can be attributed to one element: nitrogen. While a diamond is forming, nitrogen atoms will arrange in such a way that that blue light is absorbed, thus producing a yellow color. A specific grouping of nitrogen atoms is also responsible for the shading of orange diamonds, but will absorb light in both the blue and yellow spectrums.
These diamonds owe their color to a combination of intense pressure and heat. While still buried deep within the earth, these factors cause distortions in the crystal lattice that absorb green light, thus reflecting a pink hue. Ultra-rare red diamonds, which are essentially just deeply colored pink diamonds, have the same cause of color.
For the most part, blue diamonds get their color from boron. When this impurity is present, it bonds to carbon in the crystal structure, absorbing red, yellow and green areas of the color spectrum.
It’s not until the last leg of their journey to the earth’s surface that diamonds get their green color. Just as they are about to leave the uppermost layer of the crust, these stones absorbs naturally occurring radiation, which causes them to reflect a green hue by absorbing red and yellow light.
So far, all scientists are certain of is that the cause of color for purple and violet diamonds is crystal distortion. However, it is believed that the presence of hydrogen may be partly responsible for their hue.
A diamond certificate verifies each diamond’s specifications, including its color grade, carat weight, clarity grade and cut grade. You should never buy a diamond without a diamond certificate. The most well-known grading laboratories are the Gemological Institute of America (GIA) and the American Gem Society (AGS) and the International Gemological Institute (IGI).
A diamond’s cost depends upon objective characteristics, the 4C’s: Color, Clarity, Cut and Carat. The relationship between these four characteristics determines the value of a diamond. Although it is commonly assumed that carat is the most important member of the 4C’s, color, cut and clarity have a much greater impact on the appearance of a diamond.